A greenhouse study of the factors controlling the use of IPC and CIPC for the control of wild oats
(Avena Fatua)
by Tyrus Matsuoka
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree
of Master of Science in Agronomy
Montana State University
© Copyright by Tyrus Matsuoka (1953)
Abstract:
This study consisted of a series of tests designed to determine certain physical factors which may affect
the control of wild oats obtained with the use of isopropyl N-phenyl carbamate (IPC) and Isopropyl
N-(3-chlorophenyl) carbamate (CIPC). These two chemicals are two members of a large family of
carbamates being tested for their herbicidal action. Factors studied were rates of application,
comparative toxicity of IPC and CIPC to oats, differences in the reaction of wild and common oats to
IPC and CIPC, placement -of the chemicals in relation to the seed, and the effect of moisture on
control.
It was found in the experiment that two pounds- per acre of IPC gave good control of both common
and wild oats, but at least three pounds per acre is necessary for control of the same two species with
CIPC. There was no significant difference in reaction to the herbicides between wild and common oats.
The emergence of sugar beets was not affected by either of the chemicals at any of the rates used.
Placement of the chemicals in relation to the seed is an important factor in control. IPC must be within
an inch of the seed to produce good control and the CIPC must be within one-half inch to show similar
results. More effective control was obtained with placement of the chemicals above the seed.
The herbicides apparently need to be in moist soil if maximum control is to be obtained.
With the use of herbicide rates adequate to control wild oats, placement and moisture must be
considered.
Though dormancy of wild oats must be considered in any control work done, it is possible to control
wild oats with the use of these chemicals. A GREENHOUSE STUDY OF THE FACTORS CONTROLLING THE USE OF IPC
AND CIPC FOR THE CONTROL OF WILD OATS ( AVENA FATUA)
'
. .
TYRUS MATSUOKA
z
A THESIS
S u b m itte d t o th e G ra d u a te F a c u l ty
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p a r t i a l f u l f i l l m e n t o f th e r e q u ir e m e n ts
f o r t h e d e g re e o f
M a s te r o f S c ie n c e i n - Agronomy
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M ontana S t a t e C o lle g e
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H ead, M ajor D ep artm en t
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b a n . G ra d u a te Divd. s i on
• Bozeman, M ontana
May, 19^3
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ACKNOWLEDGEMENTS
The a u th o r w is h e s t o th a n k Mr. R o b e rt L. Warden f o r h i s a d v i c e ,
c o n s t r u c t i v e c r i t i c i s m , and en co u rag em en t th ro u g h o u t t h e c o u rs e o f th e
s tu d y .
The a u th o r a ls o w is h e s to e x p r e s s h i s th a n k s to D r. A. H. P o s t,
D r. E . R. H ehn, and t h e r e s t o f th e s t a f f f o r t h e i r s u g g e s tio n s i n
w ritin g t h i s th e s i s .
106714
- 3 TABLE OF CONTENTS
Page
LISTING OF TABLES......................................................................................................................... U
LISTING OF FIGURES..........................................................................................................................5
ABSTRACT................................................................................................................................................ 6
INTRODUCTION....................................................................................................................................... 7
REVIEW OF LITERATURE.......................................................
8
MATERIALS AND MF', THODS..............................................................................................................17
EXPERIMENTAL RESULTS AND DISCUSSION..............................................................................21
SUMMARY........................................................................................................................................... U2
LITERATURE CITED........................................................................................................................... k3
- U LIST OF TABLES
Page
T ab le I .
T o ta l n i t r o g e n , pH, and p e r c e n t o r g a n ic ca rb o n o f
Bozetaan S i l t Loara from two l o c a t i o n s n e a r F o r t E l l i s
i n G a l l a t i n C ounty, M ontana ................................................................. 18
T able I I .
M e c h a n ic a l a n a l y s i s o f Bozeman S i l t Loam by th e
H ydrom eter m e t h o d ........................................................................................... 18
T a b le I I I .
The e f f e c t o f r a t e s o f IPC on th e t o l e r a n c e o f common
o a t s an d su g a r b e e t s .......................................................................................PU
T a b le 7V.
The e f f e c t o f r a t e s o f IPC and CIPC on common o a t s and
su g a r b e e t s . H e rb ic id e s w ere in c o r p o r a te d i n t o th e e n t i r e
s o i l volume o f th e can .................................................................................. PU
T a b le V.
A n a ly s is o f v a r ia n c e o f th e e f f e c t o f IPC and ClPC on
w ild and common o a t s when a p p lie d a t d i f f e r e n t r a t e s . . . P6
T ab le V I.
The c o m p a ra tiv e e f f e c t s o f r a t e s o f IPC and ClpC on w ild
and common o a ts when a p p l ie d a t d i f f e r e n t r a t e s . . . . .
PB
E f f e c t o f IPC i n o n e - h a l f in c h l a y e r s a t v a r io u s d e p th s
on t h e em ergence and v ig o r o f common o a t s p la n te d two
and o n e - h a l f in c h e s d e e p . . . . . . . . . . . . . . . . .
P8
T a b le V II.
T ab le V I I I .
Ihe e f f e c t o f CIPC on th e em ergence and v ig o r o f o a t s when
o n e - h a l f in c h deep l a y e r s o f t r e a t e d s o i l w ere p la c e d a t
d i f f e r e n t d e p th s .............................................................................................3h
T a b le IX .
The e f f e c t o f th e d ep th o f se e d in g com bined w ith v a r io u s
d e p th s o f o n e - q u a r t e r in c h l a y e r s of s o i l t r e a t e d w ith
CIPC a t two p o unds p e r a c r e on em ergence, v ig o r and
e f f i c i e n c y r a t i n g of o a t s ......................................................................3U
T a b le X.
The e f f e c t o f m o is tu r e i n o b ta in in g c o n t r o l o f o a t s w ith
th e u s e o f CIPC a p p lie d i n a two in c h s u r f a c e la y e r i n
d r y s o i l o v er o a t seed one h a l f in c h d eer i n m o ist s o i l . 39
LIST OF FIGURES
P age
F ig u re I .
The e f f e c t o f r a t e s o f IPC on th e t o l e r a n c e o f common
o a t s and s u g a r b e e t s ............................................................................................22
F ig u re 2 .
The e f f e c t o f IPC and CIPC on common o a t s ......................................23
F ig u re 3.
The e f f e c t o f IPC and CIPC tr e a tm e n ts on w ild and common
o a t s ................................................................................................................................. 27
F ig u re U.
The e f f i c i e n c y r a t i n g o f IPC i n o a t c o n t r o l when p la c e d in
one h a l f in c h l a y e r s a t d i f f e r e n t d e p th s i n t h e s o i l .
Seed
was p la n te d a t a d ep th o f two and o n e - h a l f i n c h e s ...................... 29
F ig u re
The e f f i c i e n c y r a t i n g o f CIPC when p la c e d a t d i f f e r e n t
d e p th s i n th e s o i l ................................................................................................ 31
F ig u re 6 .
The e f f e c t o f d ep th o f s e e d in g w ith depth o f a p p l i c a t i o n
o f o n e - q u a r t e r in c h l a y e r s o f s o i l t r e a t e d w ith CipC a t two
pounds p e r a c r e .....................................................................................................32
F ig u re 7.
The e f f e c t o f a p p ly in g I P C i n s o i l l a y e r s o f v a r y in g
t h i c k n e s s and a t d i f f e r e n t r a t e s on th e em ergence o f o a ts . 33
-B ABSTRACT
T h is s tu d y c o n s i s t e d o f a s e r i e s o f t e s t s d e s ig n e d t o d e te rm in e c e r t a i n
p h y s i c a l f a c t o r s w h ich may a f f e c t th e c o n t r o l o f w ild o a t s o b ta in e d w ith
th e u se o f is o p r o p y l N -p h en y l c a rb a m ate (IPC ) and I s o p r o p y l N -( 3 - c h lo ro p h e n y l)
carb am ate (C IP C ). T hese two c h e m ic a ls a re two members o f a l a r g e f a m ily o f
ca rb a m a te s b e in g t e s t e d f o r ,t h e i r h e r b i c i d a l a c t i o n . F a c t o r s s tu d ie d w ere
r a t e s o f a p p l i c a t i o n , c o m p a ra tiv e t o x i c i t y o f IPC and CIPC t o o a t s , d i f ­
f e r e n c e s i n t h e r e a c t i o n o f w ild and common o a t s to IPC an d CIPC, p la c e m e n t o f t h e c h e m ic a ls i n r e l a t i o n t o th e s e e d , and t h e e f f e c t o f m o is tu r e on
c o n tro le
I t was fo u n d i n th e e x p e rim e n t t h a t two pounds- p e r a c r e o f IPC gave
good c o n t r o l o f b o th common and w ild o a t s , b u t a t l e a s t t h r e e pounds p e r
a c re i s n e c e s s a r y f o r c o n t r o l o f t h e same tw o s p e c ie s w ith CIPC. T h ere was
no s i g n i f i c a n t d i f f e r e n c e i n r e a c t i o n t o th e h e r b ic id e s b etw een w ild and
common o a t s . The em ergence o f s u g a r b e e t s was n o t a f f e c t e d by e i t h e r o f
th e c h e m ic a ls a t an y o f t h e r a t e s u s e d .
P la c e m e n t o f th e c h e m ic a ls i n r e l a t i o n to th e seed i s an im p o rta n t
f a c t o r i n c o n t r o l . IP'C■m u st b e w i t h i n an in c h o f th e s e e d to p ro d u ce goodc o n t r o l and t h e CIPC m u st be w ith i n o n e - h a l f in c h t o show s i m i l a r r e s u l t s .
More e f f e c t i v e c o n tr o l was o b ta in e d w ith p la c e m e n t o f th e c h e m ic a ls above
th e seed.
The h e r b ic id e s a p p a r e n tly n eed to b e i n m o is t s o i l i f maximum c o n t r o l
i s t o b e o b ta in e d .
W ith t h e u s e o f h e r b i c i d e r a t e s a d e q u a te t o c o n t r o l w ild o a t s , p l a c e ­
m ent and m o is tu r e m ust be c o n s id e r e d .
Though dorm ancy o f w ild o a ts m ust b e c o n s id e re d i n any c o n t r o l work
d o n e , i t i s p o s s i b l e t o c o n t r o l w ild b a t s w ith th e u se o f th e s e c h e m ic a ls .
- 7 “
INTRODUCTION
I n th e p a s t s e v e r a l y e a r s , e s p e c i a l l y s in c e th e end o f t h e Second W o rld
War,, many new h e r b i c i d e s hav e a p p e a re d on th e m a rk e t.
Of t h e s e , 2 ,Ii-D
( 2 ,li- d ic h lo r o p h e n o x y a c e tic a c id ) h a s b een th e c h e m ic a l m ost w id e ly p u b l i c i z e d
and u s e d .
W ith th e u s e o f 2 , U-D to c o n t r o l b r o a d le a v e d p l a n t s , th e weedy
g r a s s e s a re becom ing more and more o f a p ro b lem and a r e b e in g n o ti c e d more
b y th e p u b l i c .
New h e r b i c i d e s t h a t a r e s e l e c t i v e f o r g r a s s y w eeds may n o t
be th e f i n a l answ er i n c o n t r o l , b u t t h e y can h e lp i n a t o l e r a n t cro p — s u s - ■
c e p t i b l e weed s i t u a t i o n .
Of th e w eedy g r a s s e s t h a t have c r e a te d p ro b lem s f o r a good many y e a r s ,
W ild O afs ( Avena f a t u a ) , an a n n u a l, i s one o f t h e more s e r i o u s .
t h a t w ild o a t i n f e s t a t i o n s h av e in c r e a s e d i n r e c e n t y e a r s .
I t a p p e a rs
P o s s i b ly t h i s
h a s r e s u l t e d from re d u c e d c o m p e titio n from b ro a d le a v e d p l a n t s i n g r a i n
f i e l d s t r e a t e d w i t h 2,U-D.
I n a r e a s w here c ro p s su ch a s s u g a r b e e t s , f l a x ,
o r leg u m es a r e p ro d u c e d , th e u s e o f s e l e c t i v e h e r b ic id e s may be an answ er
o r a t l e a s t a p a r t i a l answ er t o t h e p ro b lem .
The h e r b i c i d e s , IPC- ( is o p r o p y l
N -phenyl carb a m ate ) an d CIPC ( is o p r o p y l N -(3 -c h lo r o p h e n y l) carb a m ate ) a r e
show ing c o n s id e r a b le p ro m ise f o r c o n t r o l l i n g w ild o a t s i n c e r t a i n c r o p s .
I t was th e purpose o f t h i s s tu d y to d eterm in e th e e f f e c t o f k in d o f
ch em ical, r a t e s o f a p p lic a tio n and p lacem ent o f th e chem ical on th e c o n tr o l
o f w ild o a t s .
—8 —
LITERATURE REVIEW
W ild o a t s ( Avena f a t u a ) } i s d i f f i c u l t to c o n t r o l b e c a u se o f i t s d e la y e d
g e r m in a tio n , s h a t t e r i n g , and c o m p e titiv e a b i l i t y .
D elay ed g e r m in a tio n o r dorm ancy o f t h e w ild o a t s e e d i s th o u g h t t o be
ca u se d b y t h e e x c lu s io n o f oxygen by th e se q d c o a t .
Atwood (3) d e m o n s tra te d
t h a t t h e s e e d c o a t , form ed b y t h e rem n a n ts o f th e o r i g i n a l o v a ry w a l l , th e
in te g u m e n ts , and th e e p id e rm is o f t h e n u c e l l u s was th e s t r u c t u r e t h a t con­
t r o l l e d g e r m in a tio n .
I n j u r y t o t h e s e e d c o a t b y s c r a tc h in g o r s e a r in g
r e s u l t e d i n in c r e a s e d g e r m in a tio n .
He o b ta in e d an a v e ra g e o f '98 p e r c e n t
‘
.
g e rm in a tio n by t h e ab o v e tr e a tm e n t w h ile w ild o a t s i n t h e check g e rm in a te d
o n ly 62 p e r c e n t.
I n c r e a s i n g t h e oxygen c o n te n t o f a c o n t r o l l e d atm o sp h ere
a ls o in c r e a s e d g e r m in a tio n . E .P .V . Jo h n so n (lb.) a ls o d e m o n s tra te d t h a t
i n j u r y o r b re a k in g o f t h e s e e d c o a t o v e r o r n e a r t h e embryo te n d e d t o i n c r e a s e
g e r m in a tio n .
Johnson (lb.) s t a t e d t h a t th e le n g th o f th e n e c e s sa ry a f t e r - r i p e n i n g
p e rio d i s h e r i t a b l e .
In h is e x p erim en ts u sin g d i f f e r e n t s o u rc e s o f see d and
c ro s s in g A. f a tu a X A .. s a t iv a , th e r e s u l t s in d ic a te d t h a t dormancy i s con­
t r o l l e d by g e n e tic f a c t o r s .
I t w a s .b e lie v e d t h a t th e a f t e r rip e n in g p ro c e s s
may c o n s is t e s s e n t i a l l y o f a s e r ie s o f changes i n th e t i s s u e s o f the seed
c o a t which r e s u l t in an in c re a s e d p e r m e a b ility to oxygen.
Dormancy may be c o n tr o lle d by th e p lacem en t o f th e f l o r e t s on th e
p a n ic l e s .
Johnson ( lb ) , in h is e x p erim en t, h a rv e ste d th e w ild o a ts j u s t a s
th e f i r s t seeds s t a r t e d to s h a t t e r and found t h a t th e f l o r e t s from n e a r e r
th e bbse o f th e p a n ic le and th e f l o r e t s n e a r e r th e o u te r t i p o f the' w horls
- 9 -
were r i p e r th a n i n th e c e n te r o f th e p a n ic le .
These seed s t h a t were r i p e r
had a s h o r te r a f te r r ip e n in g p e rio d th a n th o s e t h a t were l e s s r i p e .
The
seed from th e p rim ary f l o r e t s had a s h o r te r a f te r r ip e n in g p e rio d th an th e
seed- i n t h e seco n d ary f l o r e t s .
Johnson (lU ) found t h a t w ild o a ts seemed to undergo seco n d ary dormancy,
i . e . , a second dormancy p e rio d o r a p p a r e n tly a le n g th e n e d a f te r r ip e n in g
p e r io d , i f c e r t a i n c o n d itio n s a r i s e .
Secondary dormancy may a r i s e i f seed s
do n o t undergo a s u f f i c i e n t le n g th o f tim e f o r a f te r r ip e n in g b e fo re th e y
a re exposed to e n iv o rn m e n ta l c o n d itio n s fa v o ra b le f o r good g e rm in a tio n .
In th e s e t e s t s c a r r ie d o u t by John so n , t h e r e was a s tro n g in d ic a tio n t h a t
c o n d itio n s conducive to a f te r r ip e n in g such as c o n tin u e d c o ld , good s o i l seed r e l a t i o n s h i p , l i g h t o r absence o f l i g h t i n c e r t a i n tim e s o f th e a f t e r ­
r ip e n in g p e rio d and o th e r c o n d itio n s r e s u l t e d i n a s h o r te r dormancy p e rio d
th a n i f t h i s p e rio d was broken b e fo re s u f f i c i e n t tim e had e la p s e d .
Johnson a lso found t h a t l i g h t and te m p e ra tu re had an e f f e c t on th e
le n g th o f dormancy.
I f th e w ild o a t see d s w ere s u b je c te d t o l i g h t i n th e
e a r ly : p sn rt o f dormancy, th e dormancy p e rio d may be s h o rte n e d , b u t i f th e
seeds, were exposed "in th e l a t t e r p a r t o f . dormancy, dormancy may be le n g th -,
ehed.
Under c o n tin u o u s f r e e z in g c o n d itio n s , dormancy was sh o rte n e d .
T h is
b re a k in g o r s h o rte n in g o f dormancy by f r e e z in g was s a id t o be b ro u g h t' about
by i n j u r y to th e see d c o a t b ecau se o f c o n tr a c tin g and e x p an d in g .
W here-the
te m p e ra tu re was above f r e e z in g p a r t o f th e tim e , dormancy was le n g th e n e d .
Secondary dormancy seemed to ta k e p la ce , when th e see d s were s u b je c te d to
c o n d itio n s fo r, g e rm in a tio n and th e n fro z e n a g a in .
F re e z in g and thaw ing d id
- 10
n o t have an e f f e c t on th e g e r m i n a b i l i t y o f th e w ild o a t .
C h e p il ( 7 ) , i n C anada fo u n d t h a t w ild o a t seed p e r s i s t e d i n th e s o i l
f o r a s lo n g a s f o u r y e a r s .
He fo u n d t h a t 80 p e r c e n t o f th e se e d s g e rm in a te d
th e f i r s t y e a r , 18 p e r c e n t th e se c o n d , and two p e r c e n t t h e t h i r d .
T here
w ere two s e e d s o u t o f t h e s e v e r a l th o u sa n d p la n te d t h a t g e rm in a te d t h e
f o u rth y e a r.
He fo u n d t h a t a g r e a t m a j o r i t y o f th e s e e d s , i f b u r ie d a t
sh a llo w d e p th s i n th e s o i l w ould g e rm in a te i n May and c o u ld be d e s tr o y e d
b e f o r e th e c ro p w as sown.
C o n tr a r y to . m o st o t h e r weed s e e d s , w ild o a t s e e d s
d id n o t g e rm in a te r e a d i l y when l y i n g on t h e s u r f a c e o f t h e gro u n d .
W ild .o a t se e d s h a t t e r r e a d i l y , th u s e n a b lin g th e p l a n t t o r e s e e d i t s e l f
b e f o r e th e c r o p s a r e h a r v e s te d .
I n h i s t e s t , C h e p il (7 ) a l s o m easured t h e
d a te o f m a t u r i t y and s h a t t e r i n g a b i l i t y o f many w eeds a s com pared t o T h a tc h e r
s p r in g w h e a t.
I n th e c a s e o f w ild o a t s , .he .gave th e d a t e o f m a tu r it y t o b e
J u l y 1 8 , and t h e s h a t t e r i n g a b i l i t y to b e 70 p e r c e n t , i . e . ^ 70 p e r c e n t o f
th e seed s h a t t e r e d b e f o r e h a r v e s t tim e o f th e T h a tc h e r w h eat w hich was
a p p ro x im a te ly a m onth l a t e r .
B ib b ey (50 fo u n d t h a t f a l l c u l t i v a t i o n in c r e a s e d w ild o a t em ergence
i n t h e same f a l l o f t r e a t i n g b y ItOO p e r c e n t a s com pared t o u n t i l l e d p l o t s .
The s e e d s w ere sown on t h e s u r f a c e and t i l l e d i n o r l e f t on t h e s u r f a c e .
T h is c o rre s p o n d e d w ith C h e p il1s o b s e r v a tio n t h a t w ild o a ts ' d id n o t g e rm in a te
r e a d i l y when on t h e s u r f a c e o f t h e g ro u n d .
The i n c r e a s e due t o t i l l a g e o f
th e same p l o t s i n s p r in g em ergence was i n f i n i t e as no g e r m in a tio n to o k "place
i n th e u n t i l l e d p l o t s .
T h u rs to n (22) d e m o n s tra te d t h a t w ild o a t s can g e rm in a te fropi a number
- 11 o f d i f f e r e n t d e p th s .
I n h e r t e s t s i n th e greenhouse* sh e in d u c e d germ­
i n a t i o n from d e p th s up to n in e in c h e s .
The s e e d lin g s fro m t h i s d e p th
w ere weak and y e llo w b u t w ere grow ing n o rm a lly w ith in a m onth.
I n th e
f i e l d , em ergence o f s e e d li n g s o c c u r r e d from s e e d in g s s i x in c h e s d e e p .
There
was no e v id e n c e o f in d u c e d dorm ancy when t h e s e e d s w ere b u r i e d , even up t o
d e p th s o f 20 in c h e s .
No se e d s s u r v iv e d a t t h e s e d e p th s (down to 20 in c h e s )
a f te r th re e y e a rs.
The w ild o a t i s a v e r y good c o m p e tito r , e s p e c i a l l y when no m easu res
a r e ta k e n to c o n t r o l i t
a f t e r i t s em erg en ce.
I t g e rm in a te s m o st a b u n d a n tly
i n c o o l w e a th e r and i s a b l e t o com pete s u c c e s s f u l l y w ith m ost an n u al c r o p s .
P av ly ch en k o (2 0 ) fo u n d t h a t w ild o a t s c u t th e y i e l d o f b a r l e y by l £ p e r c e n t
and w h eat by 28 p e r c e n t .
T h is r e d u c t i o n i n c ro p y i e l d was alm o st e x a c t l y
p r o p o r t i o n a l t o th e d e g re e o f r e d u c t io n o f th e r o o t sy ste m s due t o compe­
t i t i o n w ith w ild o a t s .
W ild o a t s a r e a s e r io u s weed o f t h e c o o l e r , m a jo r c e r e a l p ro d u c in g
a r e a s o f N o rth A m erica.
N o rth D a k o ta, M ontana, W estern M in n e s o ta , N o rth e rn
S o u th D a k o ta , and t h e P r a i r i e P ro v in c e s o f Canada a r e s e r i o u s l y i n f e s t e d ■
w ith w ild o a t s .
Of th e 1 0 6 ,0 0 0 ,0 0 0 a c r e s o f cro p l a n d i n t h i s a r e a ,
6 1 , 0 0 0 ,0 0 0 a r e i n f e s t e d w ith w ild o a ts o f w hich 29, 0 0 0 ,0 0 0 a r e i n f e s t e d
s e rio u s ly (2 b ).
I n a d d i t i o n w ild o a t s i s a sesrious weed i n a number o f
W e s te rn S t a t e s in c lu d in g w in te r cro p a r e a s i n A riz o n a and C a l i f o r n i a and
i n s e v e r a l h ig h e l e v a t i o n in t e p n o u n ta i n a r e a s .
I s o p r o p y l N- p h e n y l carb a m ate (IPC) i s a g r a y is h w h ite c r y s t a l l i n e
s u b s ta n c e , s o lu b le i n some o r g a n ic s o l v e n t s , b u t i n s o l u b l e i n o t h e r s and
.
— 1*2 ■*
n e a r l y I n s o lu b le i n w a te r ( 1 3 ) .
S o l u b i l i t y i n w a te r i s a b o u t 100 ppm f o r
IPC and 80 ppm f o r CIPG ( 1 1 ) .
IPC i s n o t t r a n s l o c a t e d a s i s 2 , U-D o r.2 ,U ,5 > -T , b u t i t d o e s a c t
s y s te m ic a lly .
I n s t e a d o f c a u s in g e x c e s s iv e grow th a s do th e l a t t e r two ma­
t e r i a l s i n some c o n c e n t r a t i o n s , IPC i s a g ro w th i n h i b i t o r .
a m i t o t i c p o is o n and c a u s e s c e l l d i v i s i o n to c e a s e .
I t is , e s s e n tia lly ,
S in c e i t i s a g row th
i n h i b i t o r , th e c h e m ic a l m ust be u se d w h ile t h e p l a n t s a r e i n th e e a r l y
s ta g e s o f g ro w th .
E n n is , ( 1 0 ) , fo u n d t h a t IPC u p s e t m i t o s i s and cau sed c e l l s t o s to p
d iv id in g a t m e tap h ase or. e a r l y a n a p h a se .
m u l tin u c le a r o r to hav e a g i a n t n u c l e i .
T h is c a u se d th e c e l l s t o be
The a p i c a l p o r t i o n s o f. t h e o a t
s e e d lin g s w h ich w ere ex p o sed to IP C to o k on a b u lb o u s a p p e a ra n c e .
The
le a v e s ta k e on a d a r k g r e e n c o lo r and a f t e r a s h o r t tim e t u r n r e d d is h
brown when t h e p l a n t s a r e t r e a t e d w ith IPC.
F re e d (11) fo u n d t h a t t h e d a r k
g re e n c o l o r r e s u l t i n g fro m tr e a tm e n t w ith IPC was d i r e c t l y due t o an i n ­
c r e a s e d amount o f c h lo r o p h y l l i n t h e t i s s u e s .
The t r e a t e d p l a n t s c o n ta in e d
fro m 19 t o 28 p e r c e n t more c h lo r o p h y ll p e r u n i t o f l e a f a r e a o r p e r gram
o f d ry w e ig h t th a n co m p arab le c h e c k s.
I n c o n ju n c tio n w ith th e in c r e a s e d
c h lo r o p h y ll c o n t e n t, t h e n it r o g e n c o n te n t i n th e t r e a t e d p l a n t s was h ig h e r
th a n th e c o n t r o l .
,
S in c e IPC d o es n o t move r e a d i l y i n t h e s o i l , some m eans o f i n c o r p o r a tin g
i t i n t o th e s o i l m u st b e u s e d .
A lth o u g h IPC i s n e a r l y i n s o lu b l e i n w a te r ,
w a te r i s th e b e s t m eans t o g e t th e c h e m ic a l i n t o th e s o i l .
At l e a s t o n e -h a lf
in c h o f r a i n o r an e q u a l amount o f i r r i g a t i o n w a te r i s n e c e s s a r y t o le a c h
- 13 e f f e c t i v e am ounts o f IPC i n t o th e s o i l .
I f th e h e r b ic id e i s s p ra y e d on th e
s u r f a c e o f t h e s o i l , th o ro u g h m ix in g by d is k in g o r s i m i l a r means t o i n s u r e
good m ix in g i s n e c e s s a r y s h o r t l y a f t e r a p p l i c a t i o n i n th e a b s e n c e o f r a i n
or irrig a tio n ,
L ogan e t a l . ( l 6 ) fo u n d th r o u ^ i th e u s e o f r a d i o a c t i v e m a t e r i a l s ' t h a t
IPC te n d s to move upw ard i n t h e s o i l a f t e r an i n i t i a l downward movement w ith
w a te r .
The d a ta c o lle c te d , fro m th e t e s t s i n d i c a t e d t h a t m o st o f th e IPC
re m a in e d i n th e to p in c h o f th e s o i l ev en when le a c h e d w ith am ounts o f w a te r
e q u i v a le n t t o a t h r e e in c h r a i n f a l l .
The w a te r was allo w ed t o le a c h i n t o
th e s o i l from 2h t o 120 h o u r s w ith a d i f f e r e n c e o f 2k h o u rs b etw een each
tr e a t m e n t .
o f l e a c h in g .
No IPC was fo u n d i n th e f o u r t h in ch o f s o i l u n t i l th e t h i r d d a y
The a d d i t i o n o f th e i n i t i a l w a te r c a u s e d ,f lu s h in g o f th e
m a t e r i a l i n t o t h e s o i l , b u t t h e r e was an upward movement o f t h e IPC d u r in g
th e su c c e e d in g d ay s o f t h e e x p e rim e n t.
H igh te m p e r a tu r e s h o r te n s th e r e s i d u a l l i f e o f th e c h em ica l i n th e
s o il.
Newman e t a l . (19) fo u n d t h a t IPC l o s t i t s e f f e c t i v e n e s s c o m p le te ly
a f t e r 36 day s in c u b a tio n a t te m p e r a tu r e s r a n g in g from 10 t o 30 d e g re e s
C e n tig r a d e .
The h i g h e s t te m p e r a tu r e c a u s e d th e IPC t o lo s e , i t s t o x i c i t y t o
p l a n t s a f t e r e i g h t day 's.
The em ergence a t t h e 30 d e g re e C e n tig r a d e t r e a t ­
m ent was a s h ig h a s t h e check a t th e end o f th e e i g h t d a y s , b u t th e p l a n t s
w ere s t u n t e d t o some e x t e n t .
IPC d is a p p e a r e d e q u a l l y a s r a p i d l y a t m o is tu r e c o n te n ts from 20 t o 80
p e r c e n t o f t h e w a te r h o ld in g c a p a c i t y o f th e s o i l .
A f te r 19 d ay s in c u ­
b a t i o n , t h e m a t e r i a l h a d 'n o e f f e c t on em ergence o r v i g o r .
- lit P e r s i s t e n c e o f IPC w as a l s o in f l u e n c e d b y r a t e s .
r a t e s (o v e r 1 ,0 0 0 p o unds p e r a c re )
Even a t v e r y h ig h
th e ch em ical d id n o t p e r s i s t f o r more
th a n 39 d a y s u n d e r t h e c o n d itio n s o f th e e x p e rim e n t (19) <,
S o il ty p e p la y s an im p o r ta n t p a r t i n p e r s i s t e n c e o f th e ch e m ic a l ( 1 2 ) .
On h e a v y , p o o r ly d r a in e d c l a y s o i l s , th e r e s i d u a l a c t i v i t y h a s b e e n o b se rv e d
t o b e up to one t h i r d lo n g e r th a n on p o r o u s , w e ll d r a in e d s o i l s .
The v o l a t i l i t y o f IPC and CIPC was d e m o n stra te d b y A nderson e t a l .
(I).
I n t h e i r e x p e rim e n ts th e c h e m ic a ls w ere s p ra y e d on s u r f a c e s s i m i l a r
t o l e a f s u r f a c e s and r a t e o f e v a p o r a tio n was tim e d .
They fo u n d t h a t a lm o s t
92 p e r c e n t o f th e CIPC e v a p o ra te d i n 2h h o u rs i n te m p e ra tu re s , o f 85 t o 88
d e g re e s F a h re n h e it„
E ig h ty p e r c e n t . o f t h e IPC e v a p o r a te d a t t h e same
te m p e ra tu re r a n g e i n 2k h o u r s .
Though n e i t h e r ch em ical i s u se d e x t e n s i v e l y
a s a f o l i a r s p r a y , t h e above e x p e rim e n t d e m o n s tra te s t h a t t h e c h e m ic a ls
sh o u ld b e in c o r p o r a te d i n t o th e s o i l a s soon a s p o s s i b le a f t e r a p p l i c a t i on.
B ecause o f th e h ig h r a t e o f v o l a t i z a t i o n o f IPC and CIPC, th e G re a t W e ste rn
S ugar Company (18) i s a d v o c a tin g m ix in g th e c h e m ic a l th o r o u g h ly i n th e to p
f o u r in c h e s o f th e s o i l im m e d ia te ly o r a s soon as p o s s i b l e a f t e r a p p ly in g .
R a te s o f a p p l i c a t i o n o f th e s e c h e m ic a ls a r e in f lu e n c e d b y th e c ro p and
t h e weed t o b e c o n t r o l l e d .
A cco rd in g t o F reed and Bierm an ( 1 3 ) , r a t e s t o
u s e ra n g e from two to e i g h t pounds t e c h n i c a l IPC p e r a c r e .
In th e ir t r i a l s
p re -e m e rg e n c e a p p l i c a t i o n r a t e s ra n g e d from two t o s i x pounds p e r a c re and
p o s t em ergence a p p l i c a t i o n s ra n g e d from f o u r t o e i g h t pounds p e r a c r e .
h i s t e s t on t h e t o l e r a n c e o f p l a n t s t o IPC , E h n is (9) fo u n d many d ic o ty ­
le d o n o u s p l a n t s w hich showed v a r y in g d e g r e e s o f s u s c e p t i b i l i t y t o th e
In
- Ifp —
c h e m ic a ls .
P l a n t s i n th e s q u a s h f a m ily ( C u r c u r b ita c e a e ) and th e p o ta to
f a m ily (S o la n a c e a e ) w ere m ost a f f e c t e d .
t e s t a ls o .
B lax seemed to b e a f f e c t e d i n t h i s
E n n is u s e d a r a t h e r h ig h r a t e o f c h e m ic a l, a p p ro x im a te ly 12
pounds p e r a c r e , w h ich may a c c o u n t f o r th e i n j u r y t o many o f th e d i c o t s .
IPC and CIPC may f i n d u s e i n M ontana i n c o n t r o l l i n g a n n u a l g r a s s e s
i n sm a ll and l a r g e s e e d e d le g u m es, f l a x , .and s u g a r b e e t s .
I n t e s t s con­
d u c te d i n some o f th e W e ste rn S t a t e s , c o n t r o l o f weedy an n u a l g r a s s e s h a s
b e e n o b ta in e d i n p e a s , la d i n o c l o v e r , f l a x , and e s t a b l i s h e d s ta n d s o f a l ­
fa lfa .
F our pounds p e r a c r e was th e minimum e f f e c t i v e r a t e n e c e s s a r y f o r
p re -e m e rg e n c e a p p l i c a t i o n s i n p e a s ■( 21) arid t h r e e to f i v e pounds p e r a c r e
c o n t r o l l e d th e weedy a n n u a l g r a s s e s i n p re -e m e rg e n c e t e s t s i n la d in o
c lo v e r (Ifp)-
The u s e o f IPC f o r t h e . c o n t r o l o f c h e a tg r a s s ( Bromus t e c -
to r u m ) in e s t a b l i s h e d s ta n d s o f a l f a l f a i s . p r o m i s i n g , h ow ever, a t l e a s t
e i g h t pounds o f IPC p e r a c re a r e n eeded f o r s a t i s f a c t o r y
c o n tr o l ( 6 ) .
was e f f e c t i v e i n c o n t r o l l i n g w eeds i n A riz o n a i n f l a x t r i a l s .
found t o be v e r y t o x i c t o f l a x i n t h i s t e s t ( 2 ) .
IPC
ClPC was
R a te s o f two to t h r e e
oounds p e r a c re o f IPC a n d .CI P C Were f o u n d .to be e f f e c t i v e i n c o n t r o l l i n g
w ild o a t s w ith th e h ig h e r r a t e b e in g more c o n s i s t e n t .
T hree pounds o f
IPC p e r a c r e i s recommended f o r s u g a r b e e t s i n M ontana by th e G re a t W este rn
S ugar Company ( 1 8 ) .
IPC and CIPC s h o u ld be a p p lie d when th e r a i n f a l l
p a t t e r n c o u ld be u s e d to th e b e s t a d v a n ta g e o r i n d r y e r a r e a s , a s soon a s
th e s e e d b ed can be p r e p a r e d and i r r i g a t e d .
P re -em e rg en ce o r p r e p l a n t i n g
a p p l i c a t i o n s a r e d e s i r a b l e b e c a u s e th e c h e m ic a ls m ust b e i n c o n ta c t w ith
th e g e rm in a tin g s e e d o r young s e e d in g t o b e m o st e f f e c t i v e .
Gopd m o is tu r e
— 16 —
c o n d i t i o n s , i . e . , r a i n f a l l a t tim e o f ^nd f o llo w in g a p p l i c a t i o n a re im p o r ta n t
t o a c h ie v e good r e s u l t s .
In W ash in g to n and O regon, l a t e w i n t e r a p p l i c a t i o n s
a r e u s e d , ta k in g a d v a n ta g e o f th e r a i n f a l l p a t t e r n o f th e a r e a .
Irrig a tio n
may be n e c e s s a r y i n th e m ore a r id r e g io n s o f th e c o u n try to g e t good c o n t r o l .
T here i s n o t a g r e a t d e a l o f d i f f e r e n c e c h e m ic a lly betw een IPC and
CIPC.
The r e s i d u a l e f f e c t o f CIPC seems t o be lo n g e r ,
ra n g e t o p l a n t s i s d i f f e r e n t th e n IPC.
and th e t o x i c i t y
F reed ( 8) s t a t e s t h a t t h e two com­
pounds a r e h ig h l y s p e c i f i c i n ith e ir a c t i o n and t h a t t h e p la n t s p e c ie s w hich
one may c o n t r o l may n o t re s p o n d t o an a p p l i c a t i o n o f "the o t h e r .
A rle (2)
r e p o r t s t h a t f l a x i s one c r o p t h a t i s h i g h l y s u s c e p t i b l e to i n j u r y b y CIPC5
b u t i s t o l e r a n t to IPC.
IPC thcpi CIPC (1 8 )'.
S u g ar b e e t s a l s o seem t o show more t o l e r a n c e to
- 17 MATERIALS AMD METHODS
The m ech an ics s tu d ie d i n t h i s s e r i e s o f t e s t s w ere ( I ) p la c e m e n t o f
th e c h e m ic a l i n r e l a t i o n to t h e s e e d ; ( 2) r a t e s n e c e s s a r y t o c o n t r o l o a t s 5
(3) d e p th o f p la c e m e n t o f c h em ica l and i t s e f f e c t on c o n t r o l ; (U) d e p th
o f s e e d in g i n r e l a t i o n to d e p th o f c h e m ic a l; (5 ) co m p ariso n o f IPC and
CIPC i n c o n t r o l o f o a t s ; ( 6) co m p ariso n o f t o l e r a n c e o f w ild o a t s and
common o a t s t o IPC and CIPC; and (7 ) e f f e c t o f m o is tu r e on e f f e c t i v e n e s s
o f t h e ■c h e m ic a lS0
A l l th e t r i a l s r e p o r te d h e r e i n w ere co n d u c te d i n th e Agronomy g re e n ­
h ouse d u r in g th e w i n t e r and s p r in g o f 195>2 and 19^3»
The te m p e ra tu re i n
th e g re e n h o u s e v a r i e d from a b o u t 5U t o 97 d e g re e s F a h r e n h e i t,
The
te m p e r a tu r e d ro p p ed t o th e low a t n i g h t and th e h ig h was re a c h e d on b r i g h t ,
sunny d a y s .
The mean d a i l y te m p e r a tu r e w as a p p ro x im a te ly 68 d e g re e s
F a h re n h e it.
The s o i l u s e d i n th e t e s t s was Bozeman S i l t Loam,
c rib e d t h i s s o i l ,
B e a tty (U) d e s­
(T a b le I ) ,
T h is s o i l h a s a te n d e n c y to p u d d le w ith e x c e s s iv e w e ttin g and c r u s t
upon d r y in g .
U nder g re e n h o u se c o n d i t i o n s , i t was n e c e s s a r y t o w et th e
s u r f a c e o f th e p o ts t h a t c r u s te d t o e n a b le th e o a t a n d /o r b e e t s e e d li n g s
to em erge n o rm a lly .
C le a n , one q u a r t o i l can s w ere u s e d a s c o n t a i n e r s f o r th e s o i l f o r
each tr e a tm e n t.
u s e d i n each c a n .
One th o u s a n d grams o f s o i l on an a i r d r y b a s i s w ere
One i n c h
"of th e a i r d ry s o i l p a s s in g th r o u g h a t h r e e -
s i x t e e n in c h s i e v e w eig h ed a b o u t 229 g ram s.
The s o i l d e p th i n each can
- 18 was j u s t s l i g h t l y l e s s th a n I u 5> in c h e s .
H oles w ere punched i n th e b o tto m
o f th e c a n s t c f a c i l i t a t e w a te r in g and a llo w d r a in a g e o f any e x c e s s iv e w a tp r.
T ab le I .
L o c a tio n
T o ta l n i t r o g e n , pH, and p e r c e n t o r g a n ic carb o n o f Bozeman S i l t
Loam from two l o c a t i o n s n e a r F o r t E l l i s i n G a l l a t i n C ounty.
D ep th o f
Sample
O rg a n ic Carbon
Per cent
L o c a tio n I
3 -9 in c h e s
9-1 3
"
1 3 -2 3
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3.7UU
3.1 3 6
.6 7 3
L o c a tio n 6
•§*>8 in c h e s
8 -1 3
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1 3 -2 1
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1 .1 7 8
.6 9 6
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pH
T o ta l N
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.371
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2 .0 3
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.% 2
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6 .3
6 .8
6 .9
M e c h a n ic a l a n a l y s i s o f Bozeman S i l t Loam, b y th e H ydrom eter m etho
Sample Number
Sample I
Sample 2
O rg an ic M a tte r
P er cent
san d p e r c e n t
..s ilt per cent
c la y p e r cen t
2 7 .3
2 7 .8
U 9.63
U7.U
2U.8
2 3 .0 3
T h is s o i l i s n o r m a lly c l a s s e d a s S i l t Loam b u t th e d a t a i n d i c a t e s t h a t
i t b o r d e r s betw een loam and s i l t loam . T h is i s th e a n a l y s i s o f a sam ple
w hich was ta k e n a d j a c e n t t o t h e a r e a o f th e s o i l u s e d i n t h e e x p e rim e n t.
The c h e m ic a ls u s e d i n t h i s e x p e rim e n t w ere S t a u f f e r S n u ls iv e IPC^ and
2
O rth o , 3 -C h lo ro IPC E m u lsiv e.
The c h e m ic a ls w ere w eig h ed on a t o r s i o n b a l a n c e .
The t o t a l amount
o f ch em ica l n eed e d f o r t h e com plete t e s t was w eig h ed o u t on t h e b a s i s o f
1
' .
. ' ' ‘ ■
S t a u f f e r E m u lsiv e IPC, 2$ p e r c e n t T e c h n ic a l I s o p r o p y l N P h e n y l C arb am ate,
S t a u f f e r C hem ical Company, P a c i f i c N o rth w est D iv is io n , N o rth P o r tla n d ,O r e g o n .
2
O rth o 3 -C h lo ro IPC e m u ls iv e . A c tiv e i n g r e d i e n t , U6 p e r c e n t 3 - c h lo r o i s o p r o ­
p y l' N p h e n y l c a rb a m a te , by w e ig h t, C a l i f o r n i a S p ray C hem ical C o r p o r a tio n ,
Richm ond, C a l i f o r n i a .
- 19 .0 0 1 8 grams o f a c t i v e i n g r e d i e n t p e r can b e in g e q u iv a le n t to a two pound
p e r a c re a p p l i c a t i o n .
The c h e m ic a ls w ere m ixed i n w a te r and th e n m ixed
i n t o th e w eig h ed amount o f s o i l t o be t r e a t e d .
To. m easure e f f e c t i v e r a t e s
o f a p p l i c a t i o n o f IPG an d CIPC, th e c a n s w ere c o m p le te ly f i l l e d w ith
tre a te d s o il.
The h e r b i c i d e was ad d ed t o t h e w eig h ed am ounts o f s o i l
e q u i v a le n t to th e h ig h e s t c o n c e n tr a ti o n n eed ed i n th e p a r t i c u l a r t e s t .
Lower c o n c e n tr a ti o n s w ere o b ta in e d b y d i l u t i o n o f th e t r e a t e d s o i l w ith
a p p r o p r ia te am ounts o f u n t r e a t e d s o i l .
To m easu re th e e f f e c t o f p la c e ­
m ent o f th e h e r b i c i d e s on o a t g e r m in a tio n , a c o n s ta n t r a t e o f t r e a t e d s o i l
was p u t i n o n e - q u a r t e r o r o n e - h a l f in c h ban d s w ith th e d e p th o f th e b an d s
v a r y in g f o r ea c h tr e a tm e n t.
B ecause o f t h e v a r i a t i o n o f g e r m in a tio n o f w ild o a t s ca u se d b y d o r­
m ancy, M is s io n , a v a r i e t y o f common o a t s (A. s a t i v a ) , was u se d i n th e
c o m p lete s e r i e s o f t e s t s .
Ten s e e d s o f M is s io n o a t s p e r p o t w ere p la n te d
2 .5 in c h e s deep i n a l l th e t e s t s e x c e p t o n e , w here t h e p l a n t i n g d e p th was
a v a ria b le .
was m ade.
A co m p ariso n o f em ergence o f th e w ild o a t and th e common o a t
F i f t e e n se e d s p e r p o t w ere u s e d .b e c a u s e o f t h e u n e e r t a i n i t y
o f th e w ild o a t g e r m in a tio n .
Bozeman.
The w ild o a t se e d s w ere c o l l e c t e d n e a r
The M is s io n se e d w as F o u n d a tio n Seed grown on th e Agronomy Farm
i n Bozeman i n 19il9e
S h eared sugar, b e e t se e d s and M is s io n o a t s w ere p l a n te d i n s e v e r a l t e s t s
s e t up to m easu re th e e f f e c t o f r a t e s o f IPC and CIPC on em ergence o f th e s e
two p l a n t s .
F i f t e e n b e e t s e e d s (se g m e n ts) p e r can w ere p l a n t e d o n e - q u a r t e r
in c h deep and 10 o a t s e e d s w ere p l a n t e d 2, 5' in c h e s deep i n t h e same cans*
20 W a te rin g o f t h e tr e a tm e n ts was done from th e b ottom i n th e f i r s t two
te s ts .
The can s w ere p la c e d i n ' t h r e e - f o u r t h s ' in c h o f w a te r im m e d ia te ly
a f t e r t h e t e s t was s e t u p .
T h ere seemed t o b e enough movement o f t h e
c h e m ic a ls w ith t h e movement o f w a te r , up o r down, i n t h e c a n s t o a l t e r
th e r e s u l t s .
I n s u b s e q u e n t e x p e rim e n ts t h e s o i l was w et t o a p p ro x im a te ly
25 p e r c e n t m o is tu r e b e f o r e p l a n t i n g so t h a t movement o f th e c h e m ic a ls
w ould n o t b e an a l t e r i n g f a c t o r and no w a te r in g was done u n t i l a f t e r em er­
gence.
I n th o s e t e s t s w here movement o f th e c h e m ic a l w a s n 't a c r i t i c a l
f a c t o r , w a te r in g was done from th e to p o f th e c a n s .
The can s w ere w a te r e d
d a i l y a f t e r em ergence o f th e s e e d l i n g s .
A ll th e o a t o r b e e t s e e d li n g s t h a t em erged w ere c o u n te d .
was s t a r t e d a d ay a f t e r th e p l a n t s s t a r t e d em erg in g .
C ounting
V ig o r r e a d in g s on ■
th e o a t p l a n t s w ere ta k e n a s soon as d i f f e r e n c e s c o u ld b e e a s i l y s e e n .
S in c e t h e r e wasn* t any a p p r e c ia b le d i f f e r e n c e i n v i g o r o f th e b e e t s e e d li n g s ,
no v i g o r r e a d in g s w ere ta k e n on t h e b e e t s .
The v i g o r r e a d in g s w ere b a s e d on,
a s c a l e from 0 t o 1 0 , 0 b e in g no g ro w th a f t e r em ergence and 10 b e in g th e
v i g o r o f th e p l a n t s showing t h e m ost g ro w th .
The e f f i c i e n c y o f t h e h e r b i c i d e s was m easu red b y m u ltip ly in g th e
em ergence p e r c e n ta g e tim e s t h e v i g o r r e a d i n g s .
The p r o d u c t was d iv id e d b y
t e n so t h a t t h e r e s u l t i n g number c o u ld b e s c a le d i n r e l a t i o n t o a p e r f e c t
s c o re o f 1 0 0 .
The tr e a tm e n t w ith a s c o r e w ith 100 m ust h av e 100 p e r c e n t
s ta n d c o u p le d w ith a v i g o r r e a d in g o f t e n .
A tr e a tm e n t w ith a s c o re o f
z e ro gave co m p lete c o n t r o l i n em ergence a n d /o r c o n t r o l o f g ro w th .
T h is
- r a t i n g ( v i g o r x em ergence) w i l l be r e f e r r e d to a s th e e f f i c i e n c y r a t i n g .
21 EXPERIMENTAL RESULTS AND DISCUSSION
B ecause many o f t h e t e s t s i n t h i s g re e n h o u se e x p e rim e n t w ere r e l a t e d ,
t h e r e s u l t s and d i s c u s s io n a r e b a s e d on th e g ro u p in g o f t h e s e r e l a t e d
te s ts .
P a r t I d e a ls w ith th e e f f e c t o f d i f f e r e n t r a t e s o f IPC and CIPC
on w ild and common o a t s .
P a r t I I p r e s e n t s th e e f f e c t s o f p la c e m e n t o f
th e c h e m ic a ls i n r e l a t i o n t o th e o a t s e e d s and th e r o l e t h a t m o is tu r e p la y s
i n c o n t r o l o f th e o a t s .
P a r t H I i s a g e n e r a l d is c u s s io n on th e f a c t o r s
i n f l u e n c in g th e r e s u l t s o f th e t e s t s and g e n e r a l o b s e r v a tio n s on th e symptoms
o f i n j u r y t o th e o a t p l a n t s .
PART I .
The e f f e c t o f r a t e s o f LPC and CIPG on w ild and common o a t s
and s u g a r b e e t s .
To f i n d how much IPC was n eed ed f o r th e c o n t r o l o f o a t s , a t e s t u s in g
r a t e s ra n g in g from o n e - h a l f t o t h r e e pounds o f a c t iv e i n g r e d i e n t p e r a c r e
was c a r r i e d o u t.
F ig u r e I shows t h a t a t l e a s t one and o n e - h a l f pounds o f
a c t i v e i n g r e d i e n t p e r a c r e a r e n e e d e d f o r any c o n t r o l and twq pounds p e r
a c re a r e n eed e d f o r a lm o s t co m p lete c o n t r o l .
I t was c o n c lu d e d from t h i s
t e s t t h a t th e minimum r a t e o f IPC n eed e d f o r good c o n t r o l o f o a ts w as two
pounds a c t i v e i n g r e d i e n t p e r a c r e .
B ecause CIPC i s b e in g u s e d i n th e same m anner a s IPC, a t e s t was
p la n n e d to m easure- th e d i f f e r e n c e s b etw ee n IPC and CIPC a t v a r io u s r a t e s .
R e s u l t s ( F ig u r e 2) show t h a t IPC gave f a i r c o n t r o l o f common o a t s a t th e
one and o n e - h a l f pound p e r a c r e a p p l i c a t i o n and .a t two pounds p e r a c r e gav e
p r a c t i c a l l y 100 p e r c e n t c o n t r o l .
CIPC was l e s s e f f e c t i v e i n c o n t r o l l i n g
o a t s s in c e t h r e e pounds p e r a c re re d u c e d th e e f f i c i e n c y r a t i n g b y o n ly £0
22 -
F ig u re I .
j-guilds IP U /A cre
The e f f e c t of r a t e s of IPC on th e t o l e r a n c e n f common
o a t s and s u g a r b e e t s .
?3 -
TFTK
-CIPC
F ig u re 2.
15P/A
Pounds p e r a c re
The e f f e c t o f IPC and CIPC on common o a t s .
-
T ab le I I I .
Emergence i n p e r cent o f t o t a l seed s p la n te d
Sugar b e e ts
Common o a ts
0
92
80
93
83
95
93
100
. 5
o
7 $
1 .0 0
io 5
'2 .0 0
3.00
•
T able IV.
T reatm ent
p o u n d s /a c re
IPC
I
1|
2
2ir
3
CIPC
I
I*
2
2*
■3
Check
—
The e f f e c t o f r a t e s o f - IP C on th e to le r a n c e o f common oatS'
and su g ar b e e t s .
R ate
p o u n d s/a c re
.
2h
65
75
75
75
15
5
o
•
The e f f p c t o f r a t e s o f IP C and CIPC on common. o a ts and su g ar
b e e t s . H e rb ic id e s w ere in c o rp o ra te d i n t o the e n t i r e s o i l
" volume o f th e can®
Emergence p e r c e n t
B eets
O ats
■
67
93
100
68
15
87
10 5
3
0
107
V igor
O ats
10
U
I
I
0
82
10 5
95
88
. 80
88
90
93
88
75
9
8
8
7
6
88
98
10'
Emergence x V igor
O ats
-
■
93
27
1 .5
.3
0
79
72
7 k
62
U5
98
— 2^ ”
p e r c e n t.
T a b le IV p r e s e n t s th e p e r c e n ta g e s ta n d o f b e e t s and o a t s , th e
v i g o r o f th e o a t s , and th e e f f i c i e n c y r a t i n g o f t h e v a r io u s tr e a tm e n ts *
S in c e common o a t s , ( Avena s a t i v a ) v a r M is s io n , was u s e d th ro u g h o u t
t h e e x p e rim e n t, a t r i a l com paring th e r e a c t i o n o f w ild o a t s , Avena f a t u a ,
w ith common o a t s to IPC and CIPC tr e a tm e n ts w as conducted*
The em ergence o f common o a t s was 71 p e r c e n t i n th e check and t h a t o f
w ild o a t s was 91 p e r c e n t.
W ith such a l a r g e d i f f e r e n c e i n th e p e r c e n ta g e
em ergence i n th e c h e c k s , th e a n a l y s i s o f v a r ia n c e was com puted a s p e r ­
c e n ta g e o f t h e r e s p e c t i v e c h e c k s .
The common o a t s e e d s a p p a r e n tly had l o s t
some o f t h e i r v i g o r a s a r e s u l t o f s to r a g e u n d e r h ig h te m p e r a tu r e c o n d i tio n s .
The a n a l y s i s o f v a r ia n c e i n d i c a t e d t h a t b o th s p e c ie s r e a c t e d s i m i l a r l y t o
th e two c h e m ic a ls .
The r e s u l t s o f ( T able V) a ls o i n d i c a t e d t h a t t h e r e i s
no s i g n i f i c a n t d i f f e r e n c e b etw een th e tw d s p e c ie s o f p l a n t s i n t h e i r r e a c t i o n , t o th e t r e a t m e n t s .
T h e re .w a s, h ow ever, h i g h l y s i g n i f i c a n t d i f f e r e n c e s
among tr e a tm e n ts an d betw een c h e m ic a ls .
F ig u re 3 g iv e s th e ra n g e o f th e
e f f i c i e n c y r a t i n g w hich r e s u l t e d from th e d i f f e r e n t t r e a t m e n t s .
IPC gave
th e f u l l ra n g e from z e ro t o 1 0 0 , b u t CIPC gave o n ly a p a r t i a l c u r v e , r e ­
d u c in g t h e e f f i c i e n c y r a t i n g t o 33.
I n a l l th e s e t e s t s th e b r e a k in g p o in t i n th e IPC c u r v e s i n c o n t r o l l i n g
a b i l i t y o f b o th s p e c ie s o f o a t s u s e d was a t t h e one and o n e - h a l f pound p e r
a c re r a t e .
A cc o rd in g to th e r e s u l t s i n a l l c o m p a ris o n s, IPC w as m ore e f f e c t i v e i n
c o n t r o l l i n g o a t s th a n was CIPC.
I n t h e t r i a l w h ich com pared w f ld o a t s 'w i t h
common o a t s , IPC a t a r a t e o f t h r e e p o unds p e r a c r e p r e v e n te d common o a t
- ?6.T ab le V0
A n a ly s is o f v a r ia n c e o f th e e f f e c t o f IPC and CIPC on w ild and
common o a t s when a p p lie d a t d i f f e r e n t r a t e s .
S ource o f V a ria n c e
D eg rees Freedom
R e p lic a tio n s
R a te s
E r r o r (a)
R ep s, x R a te s
C h em icals
Cheiii. x R a te s
E r r o r (b)
R ep s, x R a te s x Chem.
P la n ts
P l a n t s x Chem.
P l a n t s x R a te s
P l a n t s x R a te s x Chem.
E rro r
T o ta l
in­
s i g n i f i c a n t t o th e 5> p e r c e n t l e v e l .
-X-X-
S ig n if ic a n t to th e I p e r ce n t l e v e l.
.3
2
6
11
I
2
9
23
I
I
2
2
19
h7
Mean S q u are
870* ■
11827**
1 81
Uoi 25-”-*
2226
6U2
391
■ 5oU
1U70
197U
673
- 27 -
Common o a t s
CipC tr e a tm e n ts
- -W ild
o a t s - IPC
,tr e a tm e n ts
O Wild o a t s
ClPC tr e a tm e n t
Common o a t s
IPC tr e a tm e n t
Pounds p e r acre
F ig u re 3
The e f f e c t of IPC and ClPC t r e a tm e n ts on w ild and
common o a t s .
- 28 -
T ab le VIi
The com parative e f f e c t s o f r a t e s o f IPC and CIPC. on w ild and
common o a ts when a p p lie d a t d i f f e r e n t r a te s '.
T re a tm e n ts
Em ergence*
% ch eck
Common O a ts
IPC
I Ib /A
2 Ib /A
3 lb /A
CIPC
I lb /A
2 lb /A
3 lb /A
V ig o r
V ig o r x em ergence
■■
33.U
23
0
107
93
93
W ild O ats
IPC •
I lb /A
2 lb /A
3 lb /A
CIPC
I lb /A
2 lb /A
3 lb /A
8
3
0
U2
9
8
96
7U
12
0
7
7
93
20
3
•0
o.
102
9
BU
7
100
3
68
68
10
0
92
39
33
-x-The a c t u a l em ergence o f th e ch eck s w ere 71 p e r c e n t f o r th e common o a t s
and 91 p e r c e n t f o r t h e w ild o a t s .
Table V II.
°
E f f e c t o f IPC i n o n e - h a lf in c h l a y e r s a t v a r io u s d ep th s on th e
emergence and v ig o r o f common o a ts p la n te d two and o n e -n a li
in c h e s deep.
D epth, o f bands
In c h e s from s u rfa c e
O-g1-1
i-ii
iW
2-2*
• 3-3*
3i-U
Check
'
Emergence
p e r c en t
87.3
83
92.3
U7.3
2.3
0
0
35
8o
V igor
V igor x emergence
9
5
2
.1
0
0
0
5
10
78.75
U.25
18.5 ■
U.73
0
0
0
17.5
80.
- 29 -
One h a lf i n . la y e r s o f IPC -depth from
su rfa c e .
F ig u re In
The e f f ic ie n c y r a t i n g o f IPC i n o a t c o n tr o l when p la c e d
i n one h a l f inch la y e r s a t d i f f e r e n t d ep th s i n th e s o i l .
Seed was p la n te d at a d e p th o f two and one h a lf in c h e s .
- 30-
em ergence, w h ile th e CIPC had an e f f i c i e n c y r a tin g o f 68 on common o a ts .
I n t h e same t r i a l , IPC a t t h r e e pounds p e r a c re p r e v e n te d w ild o a t emer­
g en ce w h ile t h e e f f e c t s o f CIPC p ro d u ced an e f f i c i e n c y r a t i n g o f 33»
E v i d e n tl y th e b r e a k in g p o i n t i n th e c u r v e s on t h e g ra p h s was n o t re a c h e d
a t t h e t h r e e pound p e r a c r e r a t e o f CIPC0
S in c e t h e r e was no s i g n i f i c a n t d i f f e r e n c e b etw een th e r e a c t i o n o f
common o a t s and w ild o a t s , no a d ju s tm e n t i s n e c e s s a r y t o a p p ly common
o a t d a t a t o w ild o a t s 0
The r e a s o n o r r e a s o n s f o r t h e d i f f e r e n c e s i n th e a c t i o n o f CIPC
and IPC a r e n o t c l e a r .
C o n s id e r a tio n sh o u ld b e g iv e n t o d i f f e r e n c e s i n
p l a n t t o l e r a n c e t o th e two c h e m ic a ls .
CIPC a t t h e r a t e s u s e d i n th e s e t r i a l s .
The o a t p l a n t s may b e t o l e r a n t t o
I f h ig h e r r a t e s w ere u s e d , t h e
b re a k in g p o i n t i n t h e c u rv e s f o r CIPC m ig h t b e r e a c h e d ,
CIPC had a te n d e n c y t o f l o c c u l a t e i n t h e w a te r e m u lsio n .
Though t h i s
p r o b a b ly w ould n o t have an y e f f e c t on t h e a c t u a l c o n c e n tr a ti o n i n t r e a t e d
s o i l , i t m ig h t hav e a f f e c t e d t o x i c i t y .
T h is w ould a ls o b e a f a c t o r i n
g e t t i n g even m ix in g o f th e ch e m ic a l i n t h e s o i l .
a c o n tro llin g f a c to r .
A v e r a g e .te m p e r a tu r e i n th e w i n t e r m onths was lo w er
th a n i n t h e s p r in g m o n th s.
re c o r d e d i n A p r i l ,
T em p eratu re may h av e b e e n
T em p eratu re s above 100 d e g re e s F a h r e n h e it, w ere
I t can b e c o n c lu d e d t h a t IPC a t two pounds p e r a c r e w as
e f f e c t i v e i n o b ta in in g good c o n tr o l, o f - b o th common and w ild o a t s , b u t CipC
d id n o t g iv e good c o n t r o l ev en a t t h e . r a t e o f t h r e e p o unds p e r a c r e ,
N e ith e h t h e em ergence n o r th e v i g o r o f t h e su g a r b e e t s was a f f e c t e d ■
b y any tr e a t m e n t .
I t seem s t h a t s u g a r b e e t s a r e t o l e r a n t t o b o th c h e m ic a ls
E f f i c i e n c y R a tin g
• 31 -
check
D epth o f l a y e r s i n in c h e s
d i f f e r e n t d e p th s i n th e s o i l .
- 32 -
lo o p
80.
"•3 3A “ U in c h l a y e r
av e. em ergence 86%
E f fic ie n c y r a t i n g
60check
Uo^
>3/U-l inch la y e r
Xl 3/U-2 inch la y er
20-
^2 3/U -3 inch la y e r
o-
-
20*-----------------
F ig u re 6 .
U----------------1
--------------1------------------1-------------------------
i
1I
%
3§
2
D ep th o f p l a n t i n g i n in c h e s
The e f f e c t o f d e p th o f s e e d in g w ith d e p th o f a p p l i c a t i o n
o f o n e - q u a r te r in c h l a y e r s o f s o i l t r e a t e d w ith CIPC
a t tw o pounds p e r a c r e .
- 33 -
0" o r s u rfa c e a p p lic a tio n
l a y e r o f t r e a t e d s o i l on
s u r f a c e o f can
211 l a y e r o f t r e a t e d s o i] on
th e s u r f a c e o f the c an .
3»' l a y e r o f t r e a t e d s o i l on
che s u r f a c e o f th e c a n .
F ig u re 7.
R ate
The e f f e c t o f a p p ly in g IRC i n s o i l l a y e r s o f v a r y in g
th i c k n e s s and a t d i f f e r e n t r a t e s on t h e em ergence o f
o a ts .
- 3h T a b le V I I I .
The e f f e c t o f CipC on th e em ergence and v ig o r o f o a t s when
o n e - h a l f in c h deep l a y e r s o f t r e a t e d s o i l w ere p la c e d a t
d i f f e r e n t d e p th s .
Depth o f la y e r s
in c h e s from s u r f a c e
Emergence
p e r cen t
V igor
95
'5o
0
5 2 .5
9 2 .5
9 2 .2
7
0
0
7
9.
9
68
0
0
37
83
83
10
90
1 - l f ■• l |- 2
2 -2 |
2 i-3
3-32
3
b
h
check
T a b le IX .
90
V igor x emergence
The e f f e c t o f th e d e p th o f s e e d in g com bined w ith v a r i o u s d e p th s
o f o n e - q u a r t e r in ch , l a y e r s o f s o i l t r e a t e d w i t h ClPC a t tw o
pounds p e r a c r e on e m erg en ce, v i g o r and e f f i c i e n c y r a t i n g o f o a t s .
D epth o f L a y e rs
in c h e s
D epth o f P l a n tin g
in c h e s .
I
II I
3 A -1
3 /U - l
3 /U -l
3
.
/ h
- l
I 3 A -2
I 3A - 2
I 3A - 2
I 3 A -2
2 3A - 3
2 3 A -3
2 3 A -3
2 3 A -3
3 3 A -U
3 3 A -U
3
3
check p l o t
ch eck ” .
ch eck "
ch eck
3
/ h
- h
3
/ h
- h
Emergence
per cent
IlO
10
95
6 7.5
95
9 2 .5
7 7 .5
80
95
9 7 .5
9 2 .5
2 .5
100
100
95
87.5
87.5
97.5
87.5
. 8o
V ig o r
Q
0
1 .5
5
7 .75
In 25
2.25
3
8 .5
7.75
In 25
0
9
9
9
9
10
9
8
. 6
S tan d x V ig o r
0
0
U3
3 k
7 k
39
17
'
'
2 k
81
76
39
0
90
90
86
79
.
88
88
70
. '1 9
.
- 35 -
up to th re e pounds a c ti v e in g r e d ie n t p e r a c r e .
N elson ( I 8) r e p o r ts t h a t in
th e t e s t s conducted by th e G re a t W estern Company emergence o f su g ar b e e ts
"was re d u c e d w ith , th e t h r e e pound p e r a c re a p p lic a tio n
PART I I 0
o
f
CIPC0
R e s u lts o f p la c a n e n t o f th e chem icals i n l a y e r s in r e l a t i o n
1 to th e o a t seed s and th e e f f e c t o f m o istu re i n c o n tr o l o f.
o a ts .
Placem ent o f th e chem icals, i n r e l a t i o n to th e seed in flu e n c e s th e
e f f e c t o f the c h e m ic a ls upon th e .oat p l a n t s ,
The chem icals w ere m ixed,
in to t h e s o i l a t a r a t e o f 2 pounds p e r a c r e and th e n p la c e d i n one h a lf
in c h l a y e r s in th e c an s, th e v a r i a b l e b e in g th e d ep th o f th e la y e rs #
The r a t &■of. a p p lic a tio n o f th e chem icals was two pounds o f a c tiv e in g re ­
d ie n t- p e r a c re i n a l l c a s e s .
T able VII g iv e s a l l th e d e p th s o f t r e a t i n g
and th e r e s u l t s o f t h e tre a tm e n ts of. th e IPC la y e r in g t e s t and Table V III
g iv e s th e same ty p e o f d a ta f o r th e CIPC t e s t .
In th e IPC la y e r in g t r i a l ,
w a te rin g was done from th e bottom o f th e c a n s.
The c h em icals p la c e d a t
l e v e l s below th e seed were m ost e f f e c t i v e which was p ro b a b ly due to th e
upward movement o f th e chem ical w ith w a te r .
The chem ical, had to be w ith in
one in c h o f th e seed to E f f e c t e m e r g e n c e ,th e l e v e l s below th e seed g iv in g
com plete c o n tr o l,
in o rd e r to g e t away from movement o f the chem ical w ith
w a te rin g when ClPC was u sed i n th e la y e r in g t e s t , th e s o i l was w e tted to
a p p ro x im a te ly 25 p e r c e n t m o is tu re b e f o r e p la n tin g and t r e a t i n g .
shown i n f ig u r e
b
I t is
t h a t th e l e v e l s o f th e IPC la y e r s above th e seed allo w ed
th e p l a n t s to em erge, b u t t h a t th e se p l a n t s showed v e ry l i t t l e v ig o r and
g row th, i f t h e t r e a t e d la y e r was w ith in an in c h of th e s e e d .
F ig u re 5 shows
t h a t ClPC should be i n c o n ta c t o r w ith in o n e -h a lf in c h above th e seed .
The
—36 —
tre a tm e n ts w ith CIPC o n e -h a lf in c h o r more below th e see d f a i l e d to c o n tro l
em ergence.
The r e s u l t s o f t h i s t e s t may have-been d i f f e r e n t had h ig h e r
r a t e s been used as i t was found in th e com parison t e s t o f ClPC and IPC
t h a t ClPC d id n o t g iv e c o n tr o l a t r a t e s below th r e e pounds p e r acre,;
A nother t e s t was d e sig n e d i n o rd e r t o d e te rm in e th e e f f e c t o f d e p th
o f see d in g on emergence c o n tr o l,
,Q u a rte r in c h la y e r s o f s o i l t r e a t e d
w ith CipC a t two pounds p e r acre w ere u se d .
The s o il was m o isten ed to
a p p ro x im a te ly 23 p e r c e n t m o is tu re b e fo re t r e a t i n g and p la n tin g .
m ents a re shown i n T able IX .
The t r e a t ­
F ig u re 6 shows t h a t th e CIPC m ust be w ith in
o n e -h a lf in c h o f th e see d to g e t good r e s u l t s .
The la y e r s im m ed iately
above -th e seed gave b e t t e r c o n tro l th a n th o se below*
Emergence and v ig o r
were red u ced i n th e check where th e seed was p la n te d a t a d e p th o f 3&
in c h e s .
The emergence i n th e o n e - h a lf and one and o n e -h a lf in c h p la n tin g
d e p th s was e a r l i e r th a n f o r th e d eep er d e p th s and t h i s may have had an
e f f e c t upon th e tim e th e s e e d lin g e n te r e d th e t r e a t e d la y e r as th e re would
n o t have been as much breakdown o f th e c h e m ic a ls .
The p re s e n c e of th e h e rb ic id e s i n amounts th a t w i l l g iv e c o n tr o l, seem
t o be m ost e f f e c t i v e i f th e y a re above th e se e d .
I f h e rb ic id e movement w ith
w a te r was n o t a c r i t i c a l f a c t o r , th e r e s u l t s in d ic a te t h a t la y e r in g above
th e se e d s w i l l g iv e a b e t t e r e f f ic ie n c y r a t i n g th a n la y e r in g below the
seeds.
I t seems t h a t th e ch em icals m ust be f a i r l y c lo s e to th e seed i f
c o n tr o l i s to be o b ta in e d .
Even a t th e two pound p e r a cre r a t e o f a p p li­
c a tio n of CIPC3 th e r e was c o n tr o l i f t h e seed was i n th e t r e a t e d la y e r
o r w ith in o n e - h a lf in c h below i t .
- 37 -
The f i e l d a p p lic a tio n o f CIPC and IPC i n la y e r s would b e a problem .
Some d e v ic e such as th e noble b la d e d r i l l , u s in g s p ra y e r a tta c h m e n ts may
p o s s ib ly be d e sig n e d .
I t i s e v id e n t t h a t th e h e rb ic id e s m ust be.m ixed
th o ro u g h ly i n th e s o i l in any method o f a p p lic a tio n .
In th e case o f s u g a r
b e e ts , th e r e i s a p o s s i b i l i t y of banding n e a r th e seed to o b ta in c o n tro l
n e a r th e b e e t s e e d lin g s and re d u c e th e amount o f chem ical needed p e r a c r e .
I t was th o u g h t t h a t th e chem icals m ight be m ost e f f e c t i v e i n con­
t r o l l i n g o a ts i f m ixed i n t o l a y e r s . o f s u rfa c e s o i l o f v a ry in g th ic k n e s s .
To determ ine t h i s , a t e s t was d e sig n e d , in which th e ch em icals a t d i f f e r e n t
r a t e s were th o ro u g h ly mixed in la y e r s o f s o i l o f d i f f e r e n t th ic k n e s s .
R a te s
o f tw o, f o u r , and s ix pounds o f IPC p e r a c re w ere a p p lie d i n z e r o , one, two
and th re e in c h l a y e r s , th e zero l a y e r b ein g a s u r f a c e a p p lic a tio n w ith no
m ix in g .
The common o a t se e d was p la n te d th r e e and o n e -q u a rte r in c h e s d eep .
As shown i n f ig u r e 7 th e r e was no c o n tro l w ith th e zero and one inch l a y e r
tre a tm e n ts a t any r a t e .
When th e IPC was mixed in. th e two in c h la y e r o f
s o i l , i t gave some c o n tr o l, red u cin g th e emergence on an average o f approx­
im a te ly UO p e r c e n t.
The t r e a t e d th r e e in c h la y e r co m p le tely c o n tr o lle d
-emergence i n th e fo u r and s ix pound p e r a c re a p p lic a tio n s and reduced th e
sta n d to I ? p e r c e n t o f th e check in th e two pound per acre a p p lic a tio n .
The r e s u l t s in d i c a t e t h a t t h e chem ical should b e w ith in an in c h of th e
seed t o o b ta in b e s t r e s u l t s .
M o istu re seems t o be n e c e s s a ry to o b ta in c o n tro l o f emergence w ith th e
use o f IPC. and CIPC.
A t e s t was conducted u sin g ClPC a t two pounds p e r
a c re and mixed i n a l a y e r two in c h e s th ic k on th e s u rfa c e o f th e c a n s.
Oat
- 38 -
seeds were p la n te d two and o n e -h a lf in c h e s deep and w a te re d .
On th e f o l ­
low ing day the CIPC in n e a r a i r d ry s o i l was a p p lie d i n two in c h la y e r s
over th e w et s o i l c o n ta in in g th e se e d .
These were th en w a tered from th e
s u rfa c e a t th r e e day i n t e r v a l s f o r each tre a tm e n t.
from zero to 1£> d a y s.
W atering d a te s v a r ie d
The p e rc e n ta g e em ergence shows t h a t some c o n tro l
was o b ta in e d when th e can s w ere w atered w ith in a week fo llo w in g tre a tm e n t,
Table X.
The two pound p e r a cre r a t e o f CIPC d id n o t re d u c e v i g o r . -
R e s u lts in d ic a te d t h a t a th r e e in c h la y e r o f tr e a t e d s o i l would g iv e
v e ry good c o n tr o l, e s p e c i a l l y i f th e seed i s w ith in an in c h of th e chem ical
and enough m o is tu re i s p re s e n t to e n a b le th e chem ical to come in c o n ta c t
w ith th e g e rm in a tin g seed or young sh o o t c lo se to th e see d .
Thurston (22)
r e p o r te d t h a t w ild o a t s e e d lin g s g e rm in a tin g from s ix in c h e s deep w ere v e r y
weak and had a y ello w c o lo r .
I f m ixing to a d e p th of f o u r in c h e s can be
accom plished i n th e f i e l d , good c o n tr o l may be o b ta in e d as th e chem ical
sh ould c o n tr o l a g r e a t m a jo r ity o f th e g e rm in a tin g o a t se e d s i n t h i s l a y e r
and w ith in an inch below .
With re d u c ed v ig o r i n th o se s e e d lin g s g e rm in a tin g
below f iv e in c h e s , th e y m ight be c o m p le te ly c o n tr o lle d w ith th e h elp o f t h e
a c tio n o f th e h e r b ic id e i n re d u c in g v ig o r .
PART I I I .
G eneral d is c u s s io n aid symptoms o f in j u r y .
W atering o f th e t e s t s seemed to be one o f th e m ost c r i t i c a l f a c to r s
i n o b ta in in g a c c u ra te r e s u l t s .
There seemed to be enough movement o f the
h e r b ic id e s w ith w a te rin g to e f f e c t th e r e s u l t s .
The ch em icals w i l l move
e i t h e r up or down, depending on th e d i r e c t i o n of w a te r movement.
39 ~
-
T a b le X0
The e f f e c t o f m o is tu r e i n o b ta in in g c o n t r o l o f o a t s 1W ith .th e
u se o f CIpC a p p l ie d i n a two - in c h s u r f a c e l a y e r i n d r y s o i l o v e r
o a t s e e d one h a l f in c h ,d e e p i n .m o ist s o i l .
T rea tm e n t - Days a f t e r tr e a tm e n t
b e f o r e w a te rin g
Check
0
Em ergence
per cent
•
3.
6
9
12
.1 5
I
. 67 , .
U5 ■
50
5o
78,5
'
78.5
Go
Em ergence ,
p e r c e n t o f ch ec k
•
- 67.1
’ 75
75 .
117
117
119
- Uo Logan e t a]» (16) found t h a t IPC moves upward i n th e s o i l as i t d r i e s .
The te m p e ra tu re c o n d itio n s, o f th e greenhouse may have s h o rte n e d th e r e s i d u a l
l i f e o f th e ch em icals t o a p o in t t h a t th e y may have h em a c tiv e f o r a v e ry
s h o r t tim e .
E v a p o ra tio n of th e chem icals fo llo w in g a p p lic a tio n would bp a c r i t i c a l
f a c t o r , e s p e c i a l l y i f th e y a r e n o t mixed i n t o th e s o i l .
Because o f th e h ig h
v o l a t i l i t y o f t h e s e c h em ica ls, i t i s n e c e s s a ry to in c o rp o ra te them in to th e
s o i l a s soon as p o s s ib le .
I t may be im p o s sib le to o b ta in th o ro u g h m ixing to
a d e p th o f fo u r in c h e s , b u t any m ixing w i l l enhance th e chances o f g e ttin g
s a t i s f a c t o r y c o n tr o l.
The symptoms o f th e a f f e c te d p la n ts a re v e ry c h a r a c t e r i s t i c when t r e a t e d
with, th e s e c h em ica ls,
c o lo r .
B uerging s e e d lin g s te n d to show a v e r y dark green
I f th e growth i s sto p p ed co m p le tely w ith o n ly th e f i r s t l e a f having
dev elo p ed , th e p l a n t s w i l l soon ta k e on a re d d ish -b ro w n c o lo r .
I t i s p o s s ib le
th e grow ing p o in t i s d e stro y e d o r t h a t th e ch em ical s to p s c e l l d iv is io n com­
p l e t e l y , a s many o f th e p la n ts o b serv ed sto p p ed growth as soon as they
em erged.
In d ig g in g in to th e s o i l where .th e emergence was c o n tr o lle d , i t
was n o te d th a t th e se e d s had g erm in ated , b u t t h a t grow th was h a lte d b e fo re
th e s e e d lin g reach ed the s u rfa c e o f th e s o i l .
g a te d stem s o f many o f th e abnormal p l a n t s .
T i l l e r s w ere b o rn e on e lo n ­
E ith e r th e r e s id u a l e f f e c t o f
th e chem ical was l o s t o r th e s e p la n ts t h a t formed t i l l e r s and culms were
more to l e r a n t to t h e c h em ica ls.
I f th e s e p la n ts w ere allow ed to grow, th e y
grew n o rm a lly to m a tu r ity and formed norm al ap p earin g p a n ic le s .
■x_
— Ui —
I t seemed t h a t th e a p ic a l p o rtio n o f th e stem o f th e o a t p la n ts were
more s u s c e p tib le to b o th h e r b ic id e s th a n th e r o o t p o r ti o n s .
Both IPC and
CIPC w i l l red u ce th e e x te n t o f r o o t developm ent,' b u t t h i s does n o t seem
enough to s to p em ergence.
Though the r e s i d u a l l i f e o f th e ch em icals was
n o t m easured, i t was a p p a r e n tly v ery s h o r t.
I t was p ro b a b ly n o t more th a n •
15 o r 20 days b e ca u se th e p l a n t s t h a t w ere a b le to form a second l e a f
e v e n tu a lly re c o v e re d from th e e f f e c t s o f t h e chem ical a.
- k2 —
SUMMARY
An e x t e n s i v e re v ie w o f t h e l i t e r a t u r e c o v e rin g th e t o x i c e f f e c t s o f
IPC and CIPC i s g iv e n .
I t h as b e e n p o in t e d o u t t h a t th e s e two c lo se ly -
r e l a t e d c h e m ic a ls have some p ro m ise f o r t h e c o n t r o l o f c e r t a i n s p e c ie s
o f p l a n t s when a p p lie d to th e s o i l *
The r e s u l t s o b ta in e d i n th e g re e n h o u s e e x p e rim e n ts magr b e sum m arized
a s f o llo w s :
I*
W ater movement i n th e s o i l may d e te rm in e t o a l a r g e d e g re e t h e
e f f e c t i v e n e s s o f th e two c h e m ic a ls s t u d i e d ,
2,
The r e s i d u a l l i f e o f th e c h e m ic a ls a p p e a re d to b e n o t more than.
IJp to 2D days*
3«
IPC i s m ore e f f e c t i v e i n
c o n t r o l l i n g b o th w ild o a t s and common
o a t s th a n i s ClPG,
U„
At l e a s t two p o u n d s o f IP C per. a c re a r e n e e d e d fo r c o n t r o l and
more th a n t h r e e pounds o f CIPC p e r a c r e a r e n eed ed fo r good
c o n t r o l ( o n ly f a i r c o n t r o l w as o b ta in e d w ith th e th r e e pound
p e r a c r e a p p l ic a t io n ) *
5>,
IPC m u st be w ith in one in c h o f th e o a t seed t o c o n t r o l em ergence
and CIPC m u st b e o n e - h a l f in c h o f t h e o a t s e e d to c o n tr o l em ergence
i f o n ly two pounds a c t i v e i n g r e d i e n t a r e used*
6*
M o is tu re m u st b e p r e s e n t f o r s e c u r in g maximum c o n t r o l w ith t h e
u s e o f e i t h e r one o f th e s e c h e m ic a ls*
7*
A t h r e e in c h l a y e r w ould c o n t r o l m ost s u s c e p t i b l e s e e d li n g s
g e rm in a tin g from d e p th s down to a t l e a s t f o u r in c h e s*
8«
Sugar b e e t s a r e t o l e r a n t to b o th / ch em icals a t r a t e s up to
t h r e e pounds p e r acre*
-
h3
-
LITERA HI HE CITED
I0
ANDERSdN5
P„5 J . P. LINDER5 and JOHN W. MITCHELL. E v a p o ra tio n of
so m e -p la n t g ro w th r e g u l a t o r s and i t s p o s s i b le e f f e c t on t h e i r a c t i v i t y .
S c ie n c e , ll6 s5 d 2 -3 o November 7, 1 9 5 2 .
20
ARLE5 Ho FRED and HOWARD P . CORDS. Chem ical c o n t r o l o f w eeds i n P u n ja b
f l a x . W e ste rn Weed C o n tr o l C o n fe re n c e R e s e a rc h P r o g r e s s R e p o rt,P p. 9 5 -9 6 . 1952.
3.
ATWOOD5 W. M. A p h y s io lo g i c a l s tu d y o f g e rm in a tio n o f Avena f a t u a .
B o t. G az. 57s 3 8 6 -U lh . 19lUo
I4..
BEATTY5 MARVIN. The e f f e c t o f a v e r a g e p r e c i p i t a t i o n o f some ch em ical '
p r o p e r t i e s o f s o i l s fro m i h r e e s o i l g ro u p s n e a r Bozeman5 M ontana.
U n p u b lish e d d a t a fro m u n d e r g r a d u a te t h e s i s . . M ontana S t a t e C o lle g e . 1 9 u 9 .
5.
BIBBEY5 R. 0 . I n f lu e n c e o f e n v iro n m en t upon g e r m in a tio n o f w ild s e e d s .
S c i . A g r ic . 16 sI l 4I - 5 0 . 1935?
6.
BRUNS5 V. F „, and C. 0 . STANBERRY. E v a lu a tio n of c h e m ic a l s p r a y s f o r
t h e c o n t r o l o f c h e a t g r a s s i n e s t a b l i s h e d a l f a l f a . W este rn Weed C o n tr o l
C o n fe re n c e R e s e a rc h P r o g r e s s R e p o r t5 Pp. 1 0 6 -1 0 7 . 1 9 5 2 .
7.
CHEPIL5 W. S. G e rm in a tio n o f weed s e e d s , I . L o n g e v ity 5 P e r i o d i c i t y
o f G e rm in a tio n ,, and V i t a l i t y o f S e e d s i n c u l t i v a t e d , s o i l . S c i . A gr.
2 6 :3 0 7 -3 1 6 . 19li6.
8.
CHYNOWETH5 S. G. C o n tr o l and E r a d i c a t i o n o f W ild O a ts . The J o u r n a l
o f th e D ep artm en t o f A g r ic u lt u r e o f South A u s t r a l i a . ^ 2 ( 3 ) :3 0 1 - 0 2 .
1938.
9.
ENNIS5 W.' B. J r .
U73-U93. 19U8.
R e sp o n ses o f c r o p p l a n t s t o IPG .
B o t. G az. 109s
10.
. Some c y t o l o g i c a l e f f e c t s o f O -is o p r o p y l- n - p h e n y l
c a rb a m a te upon a v e n a . Amer. J o u r n . Bot . 3 5 :1 5 -2 1 . 19U8.
11.
.FREED, V. H. H e r b ic id e m echanism , mode o f a c t i o n o th e r th a n a r y l
o x y a lk y l a c i d s . J o u rn . Agp. and" Food Chem. I ( I ) 4I47 -5 0 . A p r. 1953«
1 2.
. o f IPG.
13.
„ Some f a c t o r s in flu e n c in g , th e h e r b ic id e ! e f f ic a c y
Weeds I s i4S-SO. O ct. 1951«
and H. E. BIERMAN. IPC5 a new weed k i l l e r . S ta tio n
B u lle tin U83, A g r ic u ltu r a l E xperim eht S ta tio n . Oregon S ta te C o lle g e ,
C o r v a llis , Oregon. S e p t. 1 9 5 0 . '
;
- LU lL o
JOHNSON, LoPoVo G e n e ra l p r e li m i n a r y s t u d i e s on th e p h y s io lo g y o f
d e la y e d g e r m in a tio n i n Avena f a t u a . C anada. J o u r n . R es. S e c t. C.
1 3 s 2 8 3 -3 0 0 . 1 9 3 5 .
15.
JONES, LUTHER Go, and W. A. HARVEY. H e r b ic id e s an d f o r m u la tio n s t h a t
a r e i n g e n e r a l u s e in th e c o n t r o l o f weeds a s s o c ia t e d w i t h legum e
s e e d p r o d u c tio n i n C a l i f o r n i a . W este rn Weed C o n tro l C o n feren c e R e s e a rc h
P r o g r e s s R e p o rt. P p . 1 0 2 -1 0 3 . 19 5 2 .
l6 o
LOGAN, A. V ., No R. ODELL, and V. H. FREED. The u s e o f C ^ i n a s tu d y
o f th e le a c h in g r a t e o f is o p r o p y l n - p h e n y l c a rb a m a te . Weeds 2 ( 1 ) g2U-25.
1953.
17.
MITCHELL:,.. J-QHtLWo. and .EAHL- C„. MARTH. ■ S e n s i t i v i t y o £ g r a s s e s and some
c ro p s p i a n t b to IPC . S c ie n c e 1 0 6 :1 5 -1 7 . J u l y , 1 9 h 7 .
18.
NELSONi R. 1T. C o n tr o l o f w ild o a t s and v o lu n t e e r g r a i n i n su g a r b e e t s
w ith IPC. P r o c e e d in g s , J o i n t M eetin g o f .th e N o rth C e n t r a l Weed Con­
t r o l C o n fe re n c e an d The W este rn C ah ad ian Weed C o n tr o l C o n fe re n c e ,
P p . 7 3 -7 5 . D ec. 19 5 2 .
19.
NEWMAN, A. S.,.-Ho Ro Db ROSE, and H. T. DERIGO.
s o ils .
S o il S c i . 66s 3 9 3 -3 9 7 . 19L8,
20.
PAVLYCHENKO, T. E. I n v e s t i g a t i o n s r e l a t i n g to weed ,c o n tr o l i n W estern
C an ad a. Hehbage P u b l i c a t i o n S e r i e s . B u i. 2 7 :9 -2 6 . 19hO#
21.
RASMUSSEN, LOWELL W. C o n tr o l o f w ild o a t s i n p e a s . W este rn Weed Con­
t r o l C o n feren c e R e s e a rc h P r o g r e s s R e p o r t. P p. 1 0 5 -1 0 6 . 1952.
22.
THURSTON, J . M. Some e x p e rim e n ta l and f i e l d o b s e r v a tio n s on t h e
g e rm in a tio n o f w ild o a t s e e d i n s o i l and em ergence o f s e e d li n g s .
Ann. A p p i. B io l . 3 8 :8 1 2 -8 3 2 . 1952. '
P e r s i s t e n c e o f IPC i n
"
23.
TOOLE, Eo Ho an d COFFMAN, F .A. V a r i a t i o n s i n dorm ancy of s e e d o f th e
w ild o a t , Avena f a t u a . J o u r n . o f Amer. Soc. o f A g ro n . (Agronomy
J o u r n a l ) . 3 2 :6 3 1 -8 . A u g u st, 19l|0.
'2h.
WOOD, H. E . . "The W ild O a t" , o c c u rre n c e i n j o i n t c o n fe re n c e a r e a .
P ro c e e d in g s J o i n t M eetin g o f t h e N o rth C e n tr a l Weed C o n tr o l C o n feren c e
and th e W este rn C an ad ian Weed C o n tro l C o n fe re n c e . P . 2 0 , D ec. 1952.
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